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It is difficult to find reliable data on properties of benzoin. Samples may or may not be representative. For the two best balsam grades of ''S. benzoin'' ("red benzoin") and ''S. paralleloneurum'' ("white benzoin") the following data are an indication of their chemical content: insolubility in ethanol 1.2-2.8% and 1.3-3.7%, ash content 0.09-0.17% and 0.03-0.07%, cinnamic acid 0% and 24.5-30.6% and benzoic acid 26.2-27.2% and 11.5-12.9%. Sumatra benzoin is usually 75% soluble in ethanol, but when of very high quality it is 95% soluble. As Sumatra benzoin is sold in blocks its quality is variable, partly because it includes pieces and dust of "damar", the exudate from ''Dipterocarpaceae''. The aromatic compounds of the different benzoin species (balsamic acids (i.e. benzoic acids and cinnamic acids), vanillin, cinnamic-, p-coumaryl- and coniferylalcohol) are probably products of an injury-induced change to the lignin metabolism. It is unknown whether sumaresinol acid occurs in the bark or wood of non-injured trees. Unlike many other balsams, benzoin produces negligible amounts of essential oil on distillation.
Paleness and purity (without extraneous matter i.e. high alcohol solubility) are important indicators of quality. A tentative FAO/WHO specification exists for "benzoin gum" as a food additive: for Sumatra benzoin and Siam benzoin the ethanol solubility should be respectively75respectively ≥ 75% and90and ≥ 90% and the acid-insoluble ash should be respectively 1≤ 1% and 0≤ 0.5%. Pharmaceutical uses of benzoin generally require compliance with national pharmacopoeia specifications and these vary according to the pharmacopoeia and the type of benzoin. Loss on drying should usually be 10≤ 10% for both types of benzoin, but alcohol solubility is 70≥ 70-80% for Sumatra benzoin and 90≥ 90-98% for Siam benzoin. Balsamic acid content is important, and both types of benzoin are usually required to contain a minimum of 25% acids (calculated as cinnamic acid for Sumatra benzoin and benzoic acid for Siam benzoin). Total ash and acid-insoluble ash are also specified in some pharmacopoeias.
The wood is dull red to pale brown with irregular white flecks, grain very coarse, 470-710 kg/m<sup>3</sup> at 15% moisture content, rather soft, moderately strong and non-durable to slightly durable.
